Search results for " Composition"
showing 10 items of 1437 documents
Integrated analytical methodologies for the study of corrosion processes in archaeological bronzes
2011
Abstract The investigations on structure and micro-chemical composition of archaeological metal alloys are needed in archaeometry. The aim of this study is devoted both to acquire information about their provenance and production technology, and to improve our understanding about the corrosion processes. In this paper we present the study of the corrosion phenomena of bronze samples, laboratory-made according to binary, ternary and quaternary alloys typical of Roman archaeometallurgical production through an integrated methodology based on the use of non or micro invasive physical techniques. Among the analysed samples, two were artificially aged through burial in the archaeological site of…
Characterisation of the magmatic signature in gas emissions from Turrialba Volcano, Costa Rica
2014
The equilibrium composition of volcanic gases with their magma is often overprinted by interaction with a shallow hydrothermal system. Identifying the magmatic signature of volcanic gases is critical to relate their composition to properties of the magma (temperature, fO2, gas-melt segregation depth). We report measurements of the chemical composition and flux of the major gas species emitted from Turrialba Volcano during March 2013. Measurements were made of two vents in the summit region, one of which opened in 2010 and the other in 2012. We determined an average SO2 flux of 5.2 ± 1.9 kg s-1 using scanning ultraviolet spectroscopy, and molar proportions of H2O, CO2, SO2, HCl, CO and H2 ga…
Norm, essential norm and weak compactness of weighted composition operators between dual Banach spaces of analytic functions
2017
Abstract In this paper we estimate the norm and the essential norm of weighted composition operators from a large class of – non-necessarily reflexive – Banach spaces of analytic functions on the open unit disk into weighted type Banach spaces of analytic functions and Bloch type spaces. We also show the equivalence of compactness and weak compactness of weighted composition operators from these weighted type spaces into a class of Banach spaces of analytic functions, that includes a large family of conformally invariant spaces like BMOA and analytic Besov spaces.
The signature of longevity in Sicily
2019
Ageing is a natural and physiological condition that is the result of compromised stress response, homeostatic imbalance and increased risk of developing diseases. However, if aging with good health and functions (successful ageing) and aging with disease and disability (unsuccessful ageing) depends on a combination of “positive features”, including genetic, epigenetic and phenotypic characteristics in combination with favourable environment, economic status and social involvement. In our study, we summarize some key points for the identification of a longevity signature, with a particular focus on long-living Sicilian individuals and centenarians. Analysing three different Sicilian cohorts…
Aqueous enzymatic process assisted by microwave extraction of oil from yellow horn (Xanthoceras sorbifolia Bunge.) seed kernels and its quality evalu…
2013
Abstract In this study, aqueous enzymatic process (AEP) assisted by microwave extraction (ME) of oil from yellow horn ( Xanthoceras sorbifolia Bunge.) seed kernel was investigated. Central composite design (CCD) and response surface methodology (RSM) were used to optimise an enzyme cocktail (cellulase, hemicellulase, pectinase) for AEP. The main factors of ME were also studied. A maximal oil extraction yield of 55.8% was achieved under optimal conditions. Moreover, scanning electron microscope (SEM) was applied to characterise the extraction process. Analysing chemical composition of the extracted oil by GC–MS showed that the content of unsaturated fatty acids by this emerging method (91.18…
Effects of a short-term resistance program using elastic bands versus weight machines for sedentary middle-aged women.
2008
This study was designed to determine whether different effects on functional capacity and body composition were produced by using different devices (elastic bands (EBs) versus weight machines (WMs)) with the same resistance training program. Forty-five healthy sedentary middle-aged women volunteers were chosen and randomly assigned to 1 of 3 groups: 21 subjects trained using EBs (EBG), 14 in trained using WMs (WMG), and 10 were controls (CG). Both exercise groups trained with a periodized muscular endurance program twice a week for 10 weeks, with a total of 6 exercises per session for the major muscle groups. Exercise intensity was equalized by jointly monitoring the same targeted number of…
Fitness and lean mass increases during combined training independent of loading order.
2014
Although the benefits of combined endurance (E) and strength (S) training for the development of physical fitness and health are well known, scientific examination of the effect of loading order when E and S are combined into the same training session (E+S vs S+E) is rare. This study investigated the effects of moderate frequency E+S versus S+E training on physical fitness, body composition, and blood lipids.Physically active and healthy young men performed E+S (n = 16) or S+E (n = 18) training 2-3 times a week for 24 wk. Endurance (by incremental bike test) and strength (by dynamic leg press) performance as well as body composition (by dual-energy x-ray absorptiometry), muscle cross-sectio…
Frailty Is Associated with Oxidative Stress in Older Patients with Type 2 Diabetes
2021
Aging has increased the prevalence of frailty, and type 2 diabetes (T2D) has also increased in prevalence. Diabetes and oxidative stress (OS) have been shown to be related to frailty. However, the exact mechanism by which it occurs is not fully known. Our aim was to analyze body composition in community-dwelling older diabetic people treated in our center and to evaluate the possible relation between OS, frailty, and body composition. We included 100 adults older than 65 years with T2D. We found that 15% were frail and 57% were prefrail. The patients included in the nonrobust group showed increased levels of OS. Our study shows that the presence of T2D in the geriatric population is associa…
Characterization of Humic Acids from Raised Bog Peat
2014
Abstract Humic substances form most of the organic component of soil, peat and natural waters, but their structure and properties are very much dependent on the source. The aim of this study was to characterize humic acids from raised bog peat to evaluate the homogeneity of humic acids isolated from the bog bodies and to study peat humification impact on the properties of humic acids. Peat humic acids (HA) have an intermediate position between the living organic matter and coal organic matter, with their structure formed in a process where the relatively labile moieties (carbohydrates, amino acids, etc.) are destroyed, and thermodynamically more stable aromatic and polycyclic structures eme…
XRMA analysis and X-ray diffraction analysis of dental enamel from human permanent teeth exposed to hydrogen peroxide of varying pH
2019
Background This in vitroinvestigation shows how 3.3% H2O2, at different pH-values affects the enamel. Material and Methods A number of fifteen human premolars were used. The enamel of the coronal half in six of the teeth, were exposed by H2O2. Nine teeth were prepared to enamel powder. The enamel was exposed to 3.3% H2O2, at six different pH-values (pH range 4.5 - 7.0). Analyses of the topography of enamel performed by scanning electron microscope (SEM) and the chemical composition of enamel by X-ray microanalysis (XRMA). X-ray powder diffraction (XRD) analysed the crystallinity in enamel powder. Results The exposure to H2O2 at pH5.5 resulted in a decrease of O in the exposed enamel, and ch…